title: Diagnosing ectopic pregnancy and current concepts in the management of pregnancy of unknown location.
abstract: BACKGROUND
  A diagnosis of ectopic pregnancy (EP) is primarily achieved using transvaginal ultrasonography (TVS). Pregnancy of unknown location (PUL) is the term used to categorize a pregnancy in a woman with a positive pregnancy test when no pregnancy has been visualized using TVS. This review appraises current tools for the diagnosis of EP, describes the diagnostic criteria for non-tubal EP and reviews the literature on the clinical management of PUL.
  
  
  METHODS
  We performed a targeted search using the PubMed database. All articles published in the English language from January 1984 to March 2013 were screened for eligibility.
  
  
  RESULTS
  Using TVS to diagnose EP is highly sensitive (87-99%) and specific (94-99.9%). Variations exist in the criteria used for ultrasound diagnosis. Studies report that between 5 and 42% of women seen for ultrasound assessment with a positive pregnancy test have a PUL. For PUL, measurements of serum human chorionic gonadotrophin (hCG) and progesterone are used to predict pregnancy viability and therefore give an indication of the risk of an EP. Only 6-20% of PUL are subsequently diagnosed with EP. Non-tubal EPs are relatively uncommon, difficult to diagnose and result in disproportionate morbidity and mortality.
  
  
  CONCLUSIONS
  Access to expertise and equipment for high-quality TVS means the majority of women with EP in developed countries can be diagnosed rapidly and accurately. Identifying PUL, which are low risk and therefore requiring less follow-up, finding better serum markers for EP and safely identifying women who do not require intervention for EP are the current diagnostic challenges.
authors.affiliation: North Middlesex University Hospital, Sterling Way, London N18 1QX, UK.
authors.forename: E
authors.initials: E
authors.lastname: Kirk
authors.forename: C
authors.initials: C
authors.lastname: Bottomley
authors.forename: T
authors.initials: T
authors.lastname: Bourne
mesh_terms: D015415:Biomarkers / Q000097:blood; D003937:Diagnosis, Differential; D003949:Diagnostic Techniques, Surgical; D005260:Female; D006801:Humans; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000175:diagnosis* / Q000628:therapy; D012307:Risk Factors; D016216:Ultrasonography, Prenatal; D057832:Watchful Waiting
chemical_list: D015415:Biomarkers
keywords: ectopic pregnancy; expectant management; prediction models; pregnancy of unknown location; transvaginal ultrasonography